Add abstract interfaces for the transport layer.

remoting/remoting.gyp

Index: remoting/remoting.gyp
diff --git a/remoting/remoting.gyp b/remoting/remoting.gyp
index 5c69bc21a06b5d75e28de46deb0ed21da57e38d4..777ce2eab903689d03c665efbe89d1745895bf6c 100644
--- a/remoting/remoting.gyp
+++ b/remoting/remoting.gyp
@@ -803,13 +803,12 @@
         'protocol/message_reader.h',
         'protocol/negotiating_authenticator.cc',
         'protocol/negotiating_authenticator.h',
-        'protocol/pepper_channel.h',
         'protocol/pepper_session.cc',
         'protocol/pepper_session.h',
         'protocol/pepper_session_manager.cc',
         'protocol/pepper_session_manager.h',
-        'protocol/pepper_stream_channel.cc',
-        'protocol/pepper_stream_channel.h',
+        'protocol/pepper_transport_factory.cc',
+        'protocol/pepper_transport_factory.h',
         'protocol/pepper_transport_socket_adapter.cc',
         'protocol/pepper_transport_socket_adapter.h',
         'protocol/protobuf_video_reader.cc',
@@ -836,6 +835,7 @@
         'protocol/socket_reader_base.h',
         'protocol/ssl_hmac_channel_authenticator.cc',
         'protocol/ssl_hmac_channel_authenticator.h',
+        'protocol/transport.h',
         'protocol/transport_config.cc',
         'protocol/transport_config.h',
         'protocol/util.cc',